Memory loss is one of the main complaints of normal aging. Recent evidence suggests that hormonal changes accompanying menopause may partly account for memory-loss in aging women and that these memory effects can be tempered by the use of hormone replacement therapy (HRT) (Sherwin, 1994). The mechanism of these cognitive benefits remains unclear. The overall objective of this research is to delineate better the effects of HRT on memory in post-menopausal women. Previous studies of HRT have limited their assessment of memory to clinical measures focusing almost exclusively on recall ability. The proposed studies will extend our current understanding of HRT-mediated memory effects by examining multiple types of human memory within controlled experimental paradigms. In addition to examining the effects of HRT on memory, the proposed studies will also investigate normal age-associated memory impairment. Specifically, healthy postmenopausal women drawn from a representative community sample who have undergone long-term HRT and age-matched controls who have never used HRT will be compared to younger premenopausal women on tests of implicit memory (priming) and explicit memory (recalling and recognition) for verbal and non-verbal material. Beyond proving a better description of the behavioral effects of HRT, we are interested in examining potential neural mechanisms by which estrogens modulate memory function. Specifically, we are interested in dissociating memory mediated by the frontal and medial temporal lobes. To that end, event-related brain potentials (ERPs) will be recorded from 64 scalp sites during the experimental tasks in an attempt to elucidate the electrophysiological indices of HRT-related memory enhancement. Overall, this work will serve as a mens to better elucidate the type of memory changes associated with HRT and to provide an initial examination of brain-behavior associations related to the memory effects reported in HRT-using postmenopausal women.